Hey folks, I'm in charge of a group of 10 adults that will be backpacking this summer, including some first time backpackers. We're looking at coming either May 30 - June 4 or sometime between July 26 and August 4. We'll be going into Rock Harbor, then hopefully going to Chickenbone W and back. What are typical conditions like for those dates, for both weather and bugs? Is either date significantly better than the other?

My short answer is early June. If the Spring temperatures come normally or late you might just totally miss the Black Flies. They normally peak for at least 2 weeks (or longer) anywhere from mid June to mid July, although the Black flies can re-hatch again later in July if temperatures and moisture conditions are right. They could arrive earlier as well. The mosquitoes will definitely be worse in late July and there will certainly be more people then. On the flip side things might be muddier earlier in the spring.

I'm not sure if you have reviewed the park rules for groups but here is a summary review. Anything over 6 is a group. Ten persons is the max for a group. Groups are more restricted in two main ways. First, you need to stick to your itinerary. Smaller parties of 6 or less have the flexibility to change their itinerary on a daily basis. Secondly, you must only camp in designated group tent sites. No shelters and over half of all campgrounds have no group tents sites. Fortunately most of these are the more remote campgrounds on islands or paddling sites. Still, your camping choices are a bit more restricted. The one good thing about group camping is your group site for each night is reserved.

You do have the option to break up into 2 smaller groups. There is one restriction when they know you are originally really one group. The itineraries of your 2 groups need to be different enough such that the 2 groups are never in the same campground on the same night. There is a chart in the park newsletter, The Greenstone that summarizes each campground. I also believe that your 2 groups will need to still pay the additional "group" entrance fee.

With first-timers I'd probably go for July/Aug, because early June can be cold and wet and the trails almost certainly will be wet and muddy, especially with the snow they've had this winter. If you're accustomed and prepared not an issue, but for the inexperienced it could be a little much, and you will need to carry at least somewhat more weight. Expect nights in the 30s, possibly 20s, and highs in the 40s to 60s. By the end of July add 10-15 degrees, with 80s possible during the day. Trails can still be wet and muddy, but dependent on the current weather and you're more likely to have opportunities to dry out.

Bugs will most likely be worse the end of July, but I've never found them overwhelming that time of year. Bug dope usually does the trick, with headnets for insurance. As Ed points out, mid-June to mid-July tends to be the worst for bugs.

So it's a bit of a trade-off, but there's no bad time to be on the island!

I would strongly recommend late July, especially if you have some first-time backpackers. Remember that late May/early June IS spring on Isle Royale, with all of the mud and possibly even snow that implies. Isle Royale in late July/early August is a joy. The lakes might even be swimmable then.

No matter what, plan on at least one rainy day -- they're pretty common on the island.

Thanks everyone, these are some very helpful answers! I'll share all this info with my group as we decide, although it seems like late July is the time to go. This forum has been really helpful in planning the trip, beyond just this post.

How muddy can the trails be throughout the year? I've had some muddy trails at the Porcupine Mountains in early May and Pictured Rocks in mid October. It would be a pain to be in that all the time, especially for first timers.

I do know the camping regulations. I think we'll try to stay together in one group of 10 so we can all be in the same campsite. The group campsites should be fine. I have a tentative itinerary that I think should work nicely (Ranger III to Rock Harbor, first night at Three Mile - Moskey Basin - Chickenbone W - Daisy Farm - Rock Harbor, then Ranger III out the next day).

Sounds like a great trip, but with new backpackers the short section between Daisy Farm and Moskey can be tough, I call it the mini Minong, lots of up and down over rocks, can be hot on a nice day so I would add a little extra time for that section, but Moskey is certainly one of the most beautiful places on the island.

"How muddy can the trails be throughout the year? I've had some muddy trails at the Porcupine Mountains in early May and Pictured Rocks in mid October. It would be a pain to be in that all the time, especially for first timers. "

In my opinion, the Porkies are much muddier than IR, at any time. I have been told the water table is very close to the surface in the Porkies, more so than on the island. On IR, you will come across some bad spots, especially if the beavers have been busy. Part of the game. You will have a great trip.

Sounds like a great trip, but with new backpackers the short section between Daisy Farm and Moskey can be tough, I call it the mini Minong, lots of up and down over rocks, can be hot on a nice day so I would add a little extra time for that section, but Moskey is certainly one of the most beautiful places on the island.

Thanks for the heads up there. Based on the mileage that will be one of the longer days too, so I'll make sure everyone knows what to expect. Moskey does look great, so I hope it will be worth it.

Looks like so far I'm in the small minority of folks that value no or few bugs over staying warm and dry. I can tolerate mosquitoes but not the black flies. I think the other factor is my early Spring trips have actually been in nice weather and I don't remember the mud. Now that old(er) age has set in I do remember being more warm blooded in my "youth".